Details

Autor(en) / Beteiligte

• Zhang, Guangrui
• Hao, Hongbo
• Liang, Yuping
• Qiao, Yu
• Bai, Songwei
• Liu, Heyan
• Luo, Hongzhi

Titel

Atomic disorder, magnetic and electronic properties of equiatomic quaternary Heusler alloy FeRuCrSi: Experimental and theoretical investigations

Ist Teil von

• The Journal of physics and chemistry of solids, 2023-10, Vol.181, p.111541, Article 111541

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The equiatomic quaternary Heusler alloy FeRuCrSi was synthesized and its atomic ordering, magnetic properties and electronic structure were investigated experimentally and theoretically. The FeRuCrSi formed a single Heusler phase and had a lattice constant of 5.811 Å at room temperature. An L21B-type disorder related to the random occupation of Fe and Ru at 4a and 4b sites was identified in the X-ray diffraction pattern. The Curie temperature of FeRuCrSi was 346 K and the saturation magnetization at 5 K was 1.84 μB/f.u., which is smaller than the integral value of 2.00 μB required for ideal spin gapless semiconductor character and is likely related to the L21B-type disorder. First-principles calculations revealed that ordered FeRuCrSi with YII-type structure had the lowest total energy at 0 K. However, the energy difference between it and the L21B structure was only 0.09 eV/f.u., thus the L21B disorder dominated in the experimental sample because of the enthalpy of mixing and the “freezing” of high-temperature disorder at room temperature. The YII-type FeRuCrSi was a SGS with a half-metallic gap in the minority density of states (DOS) and a zero-width gap in the majority DOS. However, the L21B-type disorder disturbed the SGS character by narrowing the two gaps. The total spin moment of ordered FeRuCrSi was 2.00 μB/f.u., mainly determined by the antiparallel coupled Cr and Fe/Ru spin moments. However, the total moment was slightly reduced in L21B-type FeRuCrSi. All this suggests that the possible L21B disorder should be carefully considered when designing and synthesizing half-metals/SGS in Heusler alloys for spintronic applications. •Equiatomic quaternary Heusler alloy FeRuCrSi was synthesized successfully, which is a ferrimagnet with TC of 346 K and Ms at 5 K of 1.84 μB/f.u.•FeRuCrSi experimental sample crystallizes in a partly disordered L21B structure•L21B disorder disturbs the spin gapless semiconductor character predicted in literature•Influence of L21B disorder should be considered carefully in the design of Heusler alloys for spintronic applications